Diagnostic Aids

If the electrical circuit checks are okay and the tow/haul shift pattern is not occurring, there may be a mechanical/hydraulic condition that prevents tow/haul operation.

Inspect wiring for poor connections at PCM. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wires that could short to bare metal or other wiring. Check for wires broken inside their insulation. If diagnosing for intermittent short or open conditions, move wiring harness while observing scan tool for value changes.